Method for the preparation of novel polyacetylene-type polymers

ABSTRACT

Polymerization of acetylenic monomers is achieved by using a catalyst which is the reaction product of a tungsten compound and a reducing agent effective to reduce W(VI) to W(III) and/or IV), e.g., WCl 6 .(organo-Li, organo-Mg or polysilane). The resultant silylated polymers are of heretofore unachievable high molecular weight and can be used as precursors to a wide variety of new acetylenic polymers by application of substitution reactions.

The United States Government has rights in this invention pursuant toContract No. DE-AC04-76DP00789 between the United States Department ofEnergy and AT&T Technologies, Inc.

This application is a continuation-in-part of Ser. No. 760,433, nowabandoned.

BACKGROUND OF THE INVENTION

Doped polyacetylene, (CH)_(x), has generated a great deal of interest asan electrode material for low cost, lightweight organic batteries withpotential for high power densities. See, e.g., MacDiarmid et al., NatoConf. Ser., Molec. Met., 6 (1), 161 (1982); Chiang, Polymer, 22, 1454(1981); P. J. Nigrey et al., J. Electrochem. Soc., 129, 1270 (1982); T.Nagatomo et al., Jap. J. Appl. Phys., 22, L275 (1983); R. H. Baughman etal., Chem. Rev., 82, 209 (1982); J. Simionescu et al., Prog. Polym.Sci., 8, 133 (1982); and Masuda et al., Acct. Chem. Res., 17, 51 (1984);which disclosures are incorporated by reference herein. Whilepolyacetylene can be doped to a metallic state (-1200 S/cm), itsintractability, O₂ sensitivity, and long-term instability pose severeproblems in processing the material on a commercial scale.

In programs of synthesis directed toward conductive materials havingimproved stability and processibility, polyacetylene derivatives havebeen prepared, e.g., poly-(trimethylsilylacetylene) (PTMSA)--C(Si(CH₃)₃)═CH)--. PTMSA has been reported previously (MW 10000),Okano et al., Polym. Preprints Jap., 31, 1189 (1982), or its duplicateJ. Polym. Sci., Polym. Chem. Ed., 22, 1603 (1984); Voronkov et al., J.Polym. Sci., Polym. Chem. Ed., 18, 53 (1980); and WO 8301905 A1 (9/6/83)to Mitsubishi Chemical Ind. Co., Ltd, Chem. Abs., 99: 159660f. However,polymers of high molecular weights were not obtained using the methodsand catalysts of the prior art.

A large number of catalyst systems were surveyed in this work foractivity in polymerization of trimethylsilylacetylene, a commerciallyavailable compound. Of the wide variety of previously known alkynepolymerization catalysts evaluated, only the tungsten-based catalysts,WCl₆.Ph₄ Sn used by the prior art and (W(CO)₆ /hr/CCl₄, gave significantamounts of PTMSA. These were not, however, satisfactory in all respects.The preparation of soluble PTMSA with WCl₆.Ph₄ Sn and (W(CO)₆ /CCl₄ /hrsuffered from low and irreproducible conversions, particularly in largescale (10 g) runs. Attempts to increase conversion by use of additionalcatalyst aliquots were only marginally successful. See the last twoentries in Table 1. It proved difficult to separate the resultingpolymer from catalyst residues and Sn by-products. Okano et al. and thiswork were unable despite several attempts, to duplicate the results ofVoronkov et al., that PTMSA can be obtained using MoCl₅ as a catalyst.Their procedure yields only low molecular weight liquid oligomers ofTMSA, which are of no value for conductive polymer applications.

These difficulties, as well as the large amount of insoluble materialformed in previous approaches, spurred efforts to develop improvedmethods of PTMSA synthesis.

In this regard, methods for preparing a variety of other relatedpolymers are also inapplicable to the problem of polymerizing TMSA andrelated monomers and/or comonomers to the high molecular weightsdesirable for important applications. For example, U.S. Pat. No.3,198,766 employs a combination of metallic catalysts in thepolymerization of unsaturated organic compounds including acetylene withorganosilicon compounds containing at least one Si-H bond. U.S. Pat.Nos. 3,699,140 and 3,758,541 involve the preparation of organosiliconcompounds containing acetylenic unsaturation. U.S. Pat. No. 3,878,263involves the preparation of acrylate-functional polysiloxane polymers.U.S. Pat. No. 4,472,562 relates to stabilized polyorganosiloxanecompositions.

The catalyst WCl₆ +n-RLi, per se, is known, e.g., for metatheticcycloolefin polymerization. See, e.g., B. A. Dolgoplosk, et al., Eur.Polym. J., 15, 237 (1979). However, this catalyst has never before beenused for polymerization of acetylenic compounds.

SUMMARY OF THE INVENTION

Accordingly, it is an object of this invention to provide a new methodfor preparing silylated polyacetylenes having desired properties, e.g.,for use as dopable organic polymers, using a controllable reaction.

It is another object of this invention to provide a process forpreparing such polymers which can be used as intermediates in thepreparation of other polyacetylenic derivatives.

It is another object of this invention to provide these polymers per seas well as various derivatives which can be prepared therefrom.

Upon further study of the specification and appended claims, furtherobjects and advantages of this invention will become apparent to thoseskilled in the art.

These objects have been attained by providing a process for preparing apolyacetylenic polymer comprising polymerizing an acetylenic monomer inthe presence of an effective catalyst which is the product of a tungsten(III to VI) compound and, as a cocatalyst, a reducing agent capable ofreducing tungsten VI to tungsten III and/or IV, with the proviso thatthe cocatalyst is not an organo-Sn compound.

They have further been achieved by providing such a process wherein atleast one acetylenic monomer is of the formula R--C.tbd.C--R₄, wherein Ris R₁ R₂ R₃ Si in which each of R₁, R₂, and R₃ is C₁₋₄ (n-- orsec-)alkyl, C₂₋₄ -alkenyl, C₆₋₁₄ -aryl, C₇₋₁₇ -heteroaryl, C₇₋₁₇-alkaryl, C₇₋₁₇ -aralkyl, C₃₋₁₂ -cycloalkyl, C₂₋₄ -(n-- or sec-)-alkylwherein one CH₂ group is replaced by --O--, --S--, --COO--, or --OOC--;and C₆₋₁₄ -aryl or heteroaryl in which one aryl CH is substituted by--O--, --S--, --COO--, or --OOC--; H, or groups recited for R₁, R₂, andR₃ ; R₄ is H or one of the groups recited for R₁, R₂, and R₃ except C₂₋₄-alkenyl, with the provisos that R and R₄ must not both be H at the sametime and that the combination of R and R₄ be sterically compatible withsaid polymerication.

They have also been achieved by providing the resultant polymers per se,e.g., as prepared by the process of this invention. An especiallypreferred polymer is polytrimethylsilylacetylene.

These objects have additionally been achieved by providing a process ofpreparing a copolymer containing repeating units of --(XC═CR₄)--, and--(C(Si(CH₃)₃)═CH)-- in varying proportions. comprising reacting a silylpolymer prepared by this invention with a reagent effective to causepartial substitution of R₁ R₂ R₃ Si-groups thereof by X-, and,optionally preparing a polymer having repeating units of --(YC═CR₄)--comprising performing the substitution process above and then reactingthe resultant --(XC═CR₄)-- -containing polymer with a reagent effectiveto cause substitution of X-groups thereof by Y-. A further object is toprovide copolymers having silyl substituents, a group X as definedabove, and a group Z by sequential replacement of the PTMSA silylgroups.

DETAILED DISCUSSION

A primary feature of the process of this invention is the utilization ofa catalyst heretofore not used in conjunction with polyacetylene-typepolymerizations. Using the catalysts of this invention, polymers areachieved--in higher yields--and with controllability of microstructurewhich were heretofore not available. These polymers also have very highmolecular weights, e.g., greater than 10,000 or 30,000 and more, up toweights on the order of 10⁶. These are number average molecular weightsas conventionally measured by gel permeation chromatography inconjunction with a conventional polystyrene standard. The polymers havehigh solubility in common organic solvents, e.g., hydrocarbons, e.g.,toluene, xylenes, etc., chlorinated hydrocarbons, THF, etc., and othersas are well known. They have low O₂ sensitivity and can beconventionally doped to desired conductive or semiconductive states(e.g., using iodine vapor). Doping is conventionally reversible tostates of lower conductivity or to insulating states.

The polymers of this invention (especially PTMSA) are particularlyuseful in that their silyl substituents can be replaced to yield otherpolyacetylene derivatives including those not readily available bydirect polymerization. By appropriately selected single or sequentialsubstitution reactions, a wide range of novel substitutedpolyacetylene-type polymers can rapidly be generated having highlydesirable properties, e.g., which make them of unique interest aselectrically conductive organic polymers for uses, e.g., as electrodesin batteries having high power densities, EMP protection, hybridmicrocircuits, electrophotography, gas separation, etc. Details of theseuses are described in the literature, including several of thereferences cited above.

The catalyst employed in this invention is provided in the active formby reactively combining two components, i.e., a tungsten compoundwherein the tungsten valence state is III to VI and a co-catalyticreducing agent having a reducing power effective for reducing tungstenVI to tungsten III and/or IV. This particular combination has heretoforebeen employed for catalysis of other reactions but never for acetylenicpolymerizations. See, supra. Prior art catalysts which have beenemployed in conjunction with polyacetylene-type polymerizations havebeen composed of the tungsten component of this invention but the priorart reducing agents (e.g., organo-Sn compounds) were ineffective tosatisfactorily reduce tungsten VI to tungsten III or IV and producedreactions having many undesirable features. Consequently, the uniqueproperties of the polymers and the polymerizations of this inventionwere never achieved. These prior art catalyst combinations are,consequently, excluded from the scope of this invention and includecombinations of tungsten hexachloride with tetrabutyl tin, tetramethyltin and tetraphenyl tin. Cocatalysts such as Et₃ SiH and Ph₂ SiH₂ arealso excluded alone or in combination with the foregoing prior artcocatalysts. Thus, in general, tetraalkyl tin and organosilanecocatalysts are ineffective in accordance with this invention.

It is believed that the active catalytic species of the process of thisinvention is tungsten IV alone or in combination with tungsten III. Thistheory, of course, is not intended to limit the scope of the inventionas described herein. Accordingly, it is conceivable that tungsten III ortungsten IV compounds which have sufficient stability and handlabilitycould be used per se catalysts in accordance with this invention.However, it is greatly preferred that the more readily available andstable form of catalyst be used wherein the tungsten component describedabove is reduced in situ by the cocatalyst described above.

In general, the tungsten component and the cocatalyst are first combinedand reacted to form the reduced form of tungsten, e.g., at -70° C. to150° C., preferably and under an inert atmosphere under anhydrousconditions. The resultant active catalyst is then added, preferablydropwise, to a solution of the monomer under conditions described morefully below. However, this order of operation is not absolutelynecessary. It is possible to add one catalytic component to the monomersolution and then to initiate the polymerization by addition of theother component. It is also possible to add the monomer to the activecatalyst solution, etc.

Preferred as tungsten compounds are tungsten VI compounds with commonanions, preferably inorganic anions forming stable and inexpensivetungsten salts. The preferred compounds are the tungsten hexahalides (F,Cl, Br, I), most preferably the readily available tungsten hexachloride.Salts of mixed anions are also suitable.

The preferred cocatalysts are organo-lithium compounds, organo-magnesiumcompounds (Grignard reagents: RMgX) and polysilanes. The organo portionof the organometallic compounds is not critical and any of theconventional aliphatic and aromatic groups utilized in such compoundsare applicable. Typical such organo groups include alkyl groups, e.g.,methyl, ethyl, propyl, etc. and phenyl groups.

Another preferred class of cocatalysts is that of the polysilanes, i.e.,polymers having Si--Si bonds. The high, linear polysilane polymers canbe utilized. e.g., those disclosed in U.S. Pat. No. 4,588,801, issued onMay 13, 1986, which is incorporated by reference herein. Also utilizableare the cyclic polysilanes, typically having 4-7 ring atoms, many ofwhich are commercially available. These polysilanes are particularlyactive cocatalysts.

Similarly utilizable are compounds having metal-metal bonds whichprovide the reducing power necessary in accordance with this invention.Such compounds include those having Si--Si, P--P, S--S, Ge--Ge, As--As,Se--Se, Sn--Sn, Sb--Sb or Te--Te bonds.

The amount of catalyst utilized is not critical. Typically, from 0.001to 10 stoichiometric equivalents can be used. Preferably, about 0.03 ofa stoichiometric equivalent is utilized. The particular form of theactive catalyst is also not critical. They can be used as prepared fromthe components themselves. It is also possible to fix one of thecatalytic components on a conventional carrier such as silica, alumina,etc., thereby preparing a surface active catalyst.

The ratio of co-catalytic reducing agent component to tungsten componentcan be varied over a wide range. This ratio will have an impact on thecatalyst's activity and the resultant properties of the polymer,including molecular weight and solubility. Consequently, in addition toselection of cocatalyst structure per se, variation of the ratio of theamount of cocatalyst to the amount of tungsten component can be used tocontrol and predetermine the properties of the polymer in conjunctionwith routine preliminary orientation experiments.

The ratio of the amount of cocatalyst to the amount of tungsten catalystwill generally be selected in the range of about 0.01 to 6 equivalentsof cocatalyst based on the amount of catalyst. In general, catalyticactivity will peak at a molar ratio of cocatalyst to catalyst of about4, the precise peak in activity being routinely determinable in a givencase by conventional orientation experiments. This activity peak willcorrespond to the molar ratio at which the highest relative amount ofthe most active form of reduced tungsten is obtained. This form ispresently theorized to be tungsten IV.

In general, as the molar ratio of cocatalyst to catalyst is increased,the molecular weight of the resultant polymer will increase and thesolubility of the resultant polymer will decrease. Consequently, theratio will be selected in accordance with the desired combination ofmolecular weight and/or solubility properties necessary for thecontemplated end-use. Again, optimum ratios in this regard can beroutinely determined with a few preliminary orientation experiments.

For example, where the silylated polymer is to be used directly for thecontemplated purpose, it may be desired to optimize solubility at theexpense of somewhat lower molecular weights. On the other hand, wherethe silylated polymer is to be used as a precursor to other polymersbased on replaced silyl groups, solubility of the silyl polymer per sewill be less important. This is based on the observation that thenon-soluble polymer obtained in the process of this invention has beenshown to be insoluble not because of crosslinking, but rather because ofthe geometric structure of the polymer itself. Experiments have shownthat the non-soluble polymer is readily solubilized by bromine reaction,i.e., as a result of replacement of some of the silyl groups withsolubilizing Br groups. The solubilized material and the originalsoluble fraction have exactly the same molecular weight distribution.However, the insoluble fraction backbone is relatively enriched in thetrans-double bond isomer with respect to the cis-double bond isomer. Theratio of cocatalyst to catalyst, consequently, exercises control of thesolubility by controlling double bond geometry. This provides asignificant advantage not achievable in prior art systems.

A wide range of monomers and comonomers can be polymerized in accordancewith this invention. In general, any combination of monomers of theformula RR'R"SiC.tbd.CR'" can be used. The R--R'" groups must beselected so that the resultant stereochemistry is not too stringent forthe polymerization to proceed. Again, routine orientation experimentscan be utilized in borderline cases in order to determine applicable andinapplicable structural combinations. Generally, any reaction compatiblealiphatic or aromatic, hydrocarbon or heterocyclic moieties can be used.

Suitable groups on the silyl portion of the monomers and polymers ofthis invention include alkyl groups of 1-4 (or more, e.g., 8 or 10,etc.) C atoms, e.g., methyl, ethyl, n-propyl, isopropyl, n-butyl,sec-butyl, etc. t-Butyl will not be applicable in most cases because ofsteric hindrance effects. The corresponding unsaturated aliphatic groupsare also utilizable. Suitable aryl groups include phenyl, naphthyl, thetri-phenyls, etc. The corresponding alkaryl and aralkyl groups can alsobe utilized, e.g., benzyl. Cycloalkyl groups are also appropriate,including cyclobutyl, cyclopentyl, cyclohexyl, etc. Methylene groups inthe mentioned alkyl groups can also be replaced by --O--, --S--,--COO--, or --OOC--. The aryl groups can be substituted, especially4-substituted by conventional electron releasing groups or even groupshaving neutral electronic effects. Many other related silyl substituentscan be equivalently employed.

Suitable R⁴ groups on the monomer include hydrogen ad the same groupsmentioned above as silyl substituents except that the alkenyl groups arenot employable since they form conjugated systems with the acetylenicbond of the monomer.

As mentioned, the combination of these groups on the monomers must beselected so that the resulting stereochemistry is compatible with thepolymerization of this invention. For example, in some cases it may notbe possible to have more than two cycloaliphatic rings on the silylgroups and, generally, bis-silyl monomers will not be suitable.

In general, the reaction of this invention will not be significantlyaffected by the precise structure of the monomers being polymerized. Thewide variation in suitable monomeric structures is a major advantage forthis invention since it permits control of the solubility properties ofthe resultant polymers via control of the hydrophilicity/hydrophobicityproperties imparted by the silyl groups in accordance with conventionalconsiderations. This results from the fact that silyl groups remain inthe polymers of this invention even when the primary silylatedacetylenic polymer is subsequently reacted to replace some of the silylgroups by other desired substituents.

It is possible to prepare homopolymers of single monomers of copolymersof the mentioned monomers with each other or with other acetylenicmonomers, including acetylene itself. All of these starting materialmonomers are known, and in some cases commercially available, or can beconventionally prepared from known starting materials using knownreactions.

The polymerization reaction of this invention can be carried out over awide range of reaction conditions. Suitable temperatures include -10° C.to 150° C., preferably 25° C.-100° C. The reactions are very preferablycarried out under inert atmospheres and anhydrous conditions since thereaction is sensitive to oxygen and water. Typically, nitrogen or argonatmospheres are used. Conversions are high, e.g., 85-100% and yields aretypically 100% based on these conversions. Typical times for completeconversion are in the range of less than about 1 minute up to about 48hours in dependence upon the reaction conditions, primarily thecocatalyst. For example, using polysilanes as cocatalysts, very shortreaction times on the order of 1 minute or less are achieved. Aspreviously noted, any order of addition is possible; however, dropwiseaddition of the active catalyst to a solution of the monomer ispreferred, especially when the highest molecular weights are desired.Suitable solvents for conductance of the reaction include the samesolvents mentioned above with respect to the solubility of the resultantpolymers, e.g., hydrocarbons, chlorinated hydrocarbons, preferablyaromatic, alkanes being less effective as solubilizing agents, ethers(e.g., THF), and, generally, any reaction compatible solvents. Ingeneral, there is no significant effect of the reaction conditions onthe nature of the resultant polymer unless the solvent interreacts withthe polymer, e.g., as in the case of THF. Workup of the product polymersis fully conventional as exemplified below.

A significant aspect of this invention is the enablement of thepreparation of polymers having molecular weights of about 30,000 andhigher. The weight of 30,000 is in the approximate region whereinpolymeric chains begin to entangle and non-Neutonian flow is observed.As a result, such polymers are excellent film formers and are highlyapplicable to a wide variety of end uses. Polymers of molecular weightssignificantly less than 30,000 are not as preferred in this regard,tending to have insufficient toughness and higher crystallinity.Polymers in accordance with this invention can be prepared withmolecular weights up to 500,000 and higher, e.g., on the order of 10⁶.Typically, molecular weight distributions peak in the range of50,000-100,000. However, it is important to note that previouslyunattained molecular weights of, e.g., 10,000, 15,000, 20,000, 25,000,30,000, 35,000, etc., can now be achieved, in accordance with thisinvention, in soluble polymers.

The polymeric products of this invention are all useful per se asconductive organic polymers for the purposes mentioned above and wellknown in the literature. However, a particularly preferred use of thesilylated polymers of this invention involves their employment asprecursors to other acetylenic polymers. This use involves theapplication of conventional nucleophilic or electrophilic substitutionreactions whereby silyl groups on the polymers prepared directly inaccordance with this invention are replaced by other groups, e.g.,halides, hydrogen, acyl groups, e.g., benzoyl, acetyl and other alkanoylgroups, etc. Conventional halogenating agents are applicable, includingCF₃ OF for fluoride substitution. Conventional acylating agents are alsoapplicable, e.g., acyl chlorides such as benzoyl chloride or acetylchloride/TiCl₄ /CH₂ Cl₂. For replacement of silyl groups by hydrogenatoms, Et₄ N⁺ F⁻ or n-BuN⁺ F⁻ or related reagents can be utilized.Deuterium can be incorporated by use of deuterated solvents. Sequentialsubstitution reactions can also be utilized, thereby significantlyexpanding the scope of polymers preparable using the polymers of thisinvention as precursors.

Suitable conditions for carrying out the large body of applicablereactions can be selected in accordance with conventionalconsiderations. Essentially, these are the same as for the correspondingsubstitution reactions carried out in the prior art. Suitable solventswill include those mentioned above and also polar solvents compatiblewith the underlying substitution reaction, preferably aprotic polarsolvents, e.g., N-methylpyrrolidone, DMF, etc., or polar solvents, e.g.,H₂ O, D₂ O, etc.

In general, less than 100% desilation will occur in these reactions.Typically, desilations on the order of 2-75%, often 30-60%, are mosteasily achieved without concomitant side reactions. Desilations up to95% have also been achieved. Desilation degree can be controlled bysuitable control of reaction conditions. Generaly, as temperatureincreases, %-desilation increases. As Friedl Craft catalytic activityincreases, electrophilic desilation degree increases. Similarly, theusual solvent effects encountered in ionic reactions will play theirnormal role here.

As mentioned, the polymers per se of this invention as well as thosepreparable therefrom by substitution reactions are all employable asdopable conductive or semiconductive organic polymers, e.g., as dopabledielectrics, e.g., cast as films for any of the previously mentionedpurposes or other known purposes, e.g., as interconnects inmicroelectronic circuitry, as antistatic agents, as replacements forconventional polymers loaded with silicon or carbon for conductivityenhancement, etc. The dopability aspect of the polymers of thisinvention is fully conventional and can be achieved utilizing the priorart methods employed in conjunction with polyacetylene and relatedpolymers.

Without further elaboration, it is believed that one skilled in the artcan, using the preceding description, utilize the present invention toits fullest extent. The following preferred specific embodiments are,therefore, to be construed as merely illustrative, and not limitative ofthe remainder of the disclosure in any way whatsoever. In the followingexamples, all temperatures are set forth uncorrected in degrees Celsius;unless otherwise indicated, all parts and percentages are by weight.

EXAMPLE 1 Poly(trimethylsilylacetylene) (Inverse Addition)

To a solution of WCl₆ (2.85 g, 7.20 mmol) in 90 ml of toluene was added4.23 ml of 1.7 M PhLi solution (7.20 mmol) in a single portion. Theresulting dark red-brown mixture was allowed to stir for 30 minutes andthen transferred to a dropping funnel. The catalyst solution was addeddropwise to a solution of 20.85 g (212 mmol) trimethylsilylacetylene in120 ml toluene over a period of 30 minutes. After stirring for 16 hoursat 23° C., an aliquot of the solution analyzed by proton NMR showedconversion to be essentially complete. The viscous reaction mixture wasdiluted with eight volumes of methanol and the resulting dark yellowprecipitate collected by filtration, to yield 16 g of crude PTMSA afterdrying in vacuo. The crude polymer was slurried in toluene andgelatinous insoluble polymer separated by filtration through filter aid.Treatment of the filtrate with five volumes of methanol affordedpurified PTMSA. Two more precipitations from toluene/methanol andTHF/methanol gave 4.5 g of analytically pure soluble PTMSA as a yellowsolid. IR (KBr): UV (THF): λ_(max) 292 (ε3000), λ_(max) 250 (ε3000); ¹HNMR(CDCl₃)δ(rel. to TMS internal standard) 0.1 (br.s., 9H, Si(CH₃)₃6.6(br.s., 1H, olefinic H); ¹³ CNMR(CDCl₃).

EXAMPLE 2 Fluoride-Induced Desilation of PTMSA

A solution of 200 mg (2 mmol) of PTMSA in dry THF containing 1.5 eq. H₂O was stirred at room temperature with 800 mg (3.0 mmol) (n-Bu)₄ N⁺ F⁻.An immediate dark blue-green color developed and persisted throughoutthe 72 hr reaction period. The product was precipitated by addition often volumes of methanol. After two more precipitations from THF-methanoland drying in vacuo, 100 mg of brick-red solid was obtained. Thismaterial exhibited new bands in the infrared at 3030, 1600, and 100 cm⁻¹-consistent with partial desilation to give a PTMSA-acetylene copolymer.

EXAMPLE 3

C-bonded silyl groups are widely utilized in synthetic organic chemistryfor their ability to stabilize charges α (anions) and β (cations) to thesilicon atom, to undergo ipso replacement reactions and to function asprotecting groups for acetylenes. (See, e.g., Fleming "ComprehensiveOrganic Chemistry," Vol. 3, Bargon, et al., Eds. Pergammon Press,Oxford, 1979, 541-686, whose disclosure is incorporated by referenceherein). It has been found that silyl groups of the polymers of thisinvention are subject to replacement with groups such as hydrogen oracetyl, etc., to give copolymers of TMSA with acetylene andacetylacetylene, respectively. Nucleophilic partial desilation wasaccomplished by treatment of a THF solution of PTMSA with Et₄ N⁺ F⁻ atroom temperature to give soluble TMSA-acetylene copolymer. The new bandsin the infrared at 3030, 1600 and 1000 cm where characteristics ofpolyacetylene and showed that the expected desilation had occurred. Thismethod has a major advantage over the desilation method used by Okano,et al. in that the desilated product is soluble and tractable over awide range of degrees of desilation and the amount of desilation couldbe varied from a few percent to >90% by judicious choice of reactionconditions, as discussed above. The resulting polymers have higherconductivities than PTMSA or any other polyacetylene derivative known.

EXAMPLE 4

Electrophilic replacement of the silyl functions in PTMSA with acetylgroups was also performed using AcCl/TiCl₄ /CH₂ Cl₂, -84°. Under theseconditions, 50% of the silyl groups were replaced. A similar replacementwas achieved using benzoyl chloride to produce the novel polyacetylenecopolymer, poly(benzoylacetylene/trimethylsilylacetylene). Similarlyutilizing CF₃ OF, the novel polymer poly(fluoroacetylene) was prepared.

EXAMPLE 5

                  TABLE 1                                                         ______________________________________                                        TMSA Polymerization by Mixtures of WCl.sub.6                                  and Organometallics                                                                                Yield    %                                               Composition T(hr).sup.a                                                                            (%).sup.b                                                                              Soluble                                                                              M.sub.n.sbsb.3.sup.c                     ______________________________________                                        WCl.sub.6.1 -n-BuLi                                                                       24       43       83     9 × 10.sup.3                       WCl.sub.6.2 -n-BuLi                                                                       24       49       32     1.1 × 10.sup.4                     WCl.sub.6.3 -n-BuLi                                                                       18       86        8     --                                       WCl.sub.6.4 -n-BuLi                                                                       24       100       4     2.5 × 10.sup.5                     WCl.sub.6.5 -n-BuLi                                                                       24        9        0     --                                       WCl.sub.6.6 -n-BuLi                                                                       24 (60°).sup.d                                                                  100       0     --                                       WCl.sub.6.2MeMgBr                                                                         24       50       100    9 × 10.sup.3                       WCl.sub.6.2PhLi                                                                           24       66       44     1 × 10.sup.4                       WCl.sub.6.2 -n-BuLi                                                                       18.sup.e 40       100    4 × 10.sup.3                       WCl.sub.6.1PhLi                                                                           16.sup.f 77       30     5 × 10.sup.4                       WCl.sub.6.Ph.sub.4 Sn.sup.g                                                               22       55       25     1.8 ×  10.sup.4                    W(CO).sub.6 /CCl.sub.4 /hr.sup.g                                                          22       57       25     2.5 × 10.sup.4                     ______________________________________                                         .sup.a Reaction conditions except where noted: (TMSA).sub.o = 1 --M in        toluene. (Cat) = 0.03 --M, T = 23° C.                                  .sup.b As isolated by MeOH precipitation                                      .sup.c Modal M.sub.n from GPC relative to polystyrene standards               .sup.d No apparent reaction at 23° C.                                  .sup.e Et.sub.2 O solvent                                                     .sup.f Inverse addition                                                       .sup.g Prior art catalyst                                                

EXAMPLE 6

I₂ -doped PTMSA of an ultimate conductivity of about 10⁻⁴ S/cm wasachieved by conventional doping. This is slightly higher than mostsubstituted polyacetylenes, but at the doping level required to achievethis value, the iodine was quite labile, desorbing readily atatmospheric pressure. Essentially all of the dopant could be removedfrom the PTMSA pellets by pumping overnight. The pellets return almostto their undoped conductivity after pumping. Desilation of PTMSA withfluoride gave copolymers of higher conductivity. Removal of 5% of thesilyl groups increased conductivity ten-fold. The solubility of theresulting copolymers, combined with their increased conductivitiesestablished their utility in the applications mentioned herein.

EXAMPLE 7 Poly(trimethylsilylacetylene) (W(CO)₆ /(PhMeSi)_(n) /hνcatalysis)

A solution of W(CO)₆ (40 mg, 0.11 mmol), purified (PhMeSi)_(n) oligomers(272 mg, 2.27 mmol), and trimethylsilylacetylene (TMSA, 700 mg, 7.12mmol) in 5 ml dry, deoxygenated benzene was irradiated under N₂ in aRayonet photochemical reactor equipped with 3500 A lamps.

After 18 hrs, the solution had gelled to a completely solid mass. Thiswas converted to a stirrable slurry by addition of 30 ml CCl₄. Solidpolymer was isolated by filtration to provide 360 mg of lemon yellowPTMSA. The infrared spectrum of this material was identical to that ofPTMSA prepared using the WCl₆.nRM catalysts, with the exception of smalladditional absorptions at 1158, 1013, and 928 cm⁻¹ attributable toslight contamination with the (PhMeSi)_(n) cocatalyst.

EXAMPLE 8 Poly(trimethylsilylacetylene) (WCl₆ /PhMeSi_(n) Catalysis)

Purified (PhMeSi)_(n) oligomers (364 mg, 2.89 mmol) were dissolved in 7ml of toluene. Upon addition of 95 mg WCl₆ (0.26 mmol) to this solution,the deep blue color of the WCl₆ was immediately discharged and a rustred color formed. The resulting mixture was allowed to stir for 30 min.and 700 mg TMSA (7.12 mmol) then added by syringe. After stirring for 24hrs at ambient temperature, the polymer product was isolated byprecipitation with 8 volumes of MeOH followed by filtration. To removetraces of (PhMeSi)_(n) cocatalyst, the crude polymer was slurried in 50ml warm hexanes, the slurry centrifuged, and the hexane supernatantdiscarded. After drying, 360 mg PTMSA was obtained with IR identical toPTMSA prepared using the WCl₆.nRM catalysts and a GPC-determined M_(w)of 23700.

EXAMPLE 9 Polymerization of TMSA in tetrahydrofuran (THF)

A solution of WCl₆ (95.2 mg, 0.26 mmol) was prepared in 7 ml dry,deoxygenated THF and immediately treated with 0.37 ml (0.53 mmol) ofn-BuLi solution in hexane. After stirring the resulting mixture for 30min. at ambient temperature, neat TMSA (700 mg, 7.12 mmol) was added bysyringe. After further stirring for 24 hrs, crude polymer wasprecipitated from this mixture by addition of 8 volumes of methanol.After reprecipitation from THF with methanol, 300 mg of lemon yellowsoluble polymer was obtained. Surprisingly, the infrared of thismaterial showed absorptions in the 1370-1480 cm⁻¹ and 1050-1150 cm⁻¹regions not found in authentic PTMSA attributable to THF-derivedmoieties. The NMR spectrum confirmed this, exhibiting strong, broadabsorptions centered at 1.6 ppm and 3.4 ppm superimposed on the usualPTMSA spectrum. Two rationalizations can be given for theseobservations: (1) the PTMSA is admixed with poly-THF or (2) THF moietieshave been grafted onto the PTMSA backbone by silyl replacement duringpolymerization. Although a rigorous distinction between these twopossibilities has not been made, the fact that two further THF/MeOHprecipitations had no effect on the ratio of the NMR integrals of the3.4 ppm (THF-derived) absorption and the 0.2 ppm absorption (PTMSA-SiMe₃groups) suggests the latter explanation to be most likely. This(assumed) TMSA-4-hydroxybutylacetylene copolymer is a better film formerthan PTMSA and, being more polar, adheres to surfaces better.

EXAMPLE 10 Bromination of Soluble and Insoluble PTMSA and Nature ofInsoluble Fraction

Samples of insoluble and soluble PTMSA fractions (50 mg each) from asingle PTMSA preparation using WCl₆.PhLi as catalyst were separatelyslurried (or dissolved) in 20 ml CCl₄. Each solution was then separatelytreated with 0.0895 g (1.1 eq) of elemental bromine. After stirring bothmixtures for 30 min. at ambient temperature, it was noted that theinsoluble fraction had been completely solubilized. After stirring for afurther 18 hrs at room temperature, excess aqueous NaHSO₃ solution wasadded to both solutions to destroy any unreacted bromine. The CCl₄layers were then separated, dried over CaSO₄, and stripped to dryness.NMR and IR spectra of the resulting brominated insoluble and solublePTMSA fractions were nearly identical. GPC determination showed that themolecular weight distributions of the two fractions were, withinexperimental error, identical. These experiments demonstrate that, forat least some of the synthetic modifications of soluble PTMSA describedin the examples, insoluble PTMSA can be utilized with equal facilitysince it is solubilized by the modification reaction. This means thatessentially all of the PTMSA generated by the polymerization of TMSA ispotentially usable in at least some derivatization reactions.

These experiments also indicate that the insoluble PTMSA is notinsoluble by virtue of crosslinking, since this crosslinking would beunaffected by the bromination reaction. The GPC molecular weightdistributions indicate that there is no significant difference inmolecular weight between the soluble and insoluble fractions. It,therefore, appears most likely that the insolubility of this fraction isdue to a greater relative number of E double bonds in its backbone thanthe soluble fraction.

EXAMPLE 11 Partial Replacement of PTMSA Silyl Groups with Fluorine

A solution of PTMSA (300 mg, 3.05 meq) in 50 ml dry, deoxygenated CH₂Cl₂ was cooled to -78° under an argon atmosphere. Gaseous CF₃ OF dilutedwith Ar was then bubbled through the solution at such a rate that thetemperature of the solution did not rise above -60° C. The PTMSAsolution immediately turned dark green upon introduction of the CF₃OF/Ar mixture and the color became progressively darker as reactionproceeded. After 10 min., the CF₃ OF flow was stopped and pure Arbubbled through the mixture as it was allowed to warm to ambienttemperature. Excess aqueous Na₂ S₂ O₃ solution was then added and themixture allowed to stir vigorously for 20 min. to destroy any unreactedCF₃ OF. The layers were then separated and 5 volumes methanol added tothe CH₂ Cl₂ phase to precipitate the crude product (120 mg). A furtherprecipitation from CDCl₃ with methanol gave 73 mg of purifiedfluoroacetylene/trimethylsilylacetylene copolymer. The IR spectrum ofthis material exhibited strong new absorption in the 1200-1000 cm⁻¹region attributable to C--F bonds and a strong shift in the C═C stretchfrom 1570 cm⁻¹ in PTMSA to 1620 and 1700 cm⁻¹ in the copolymer,consistent with C═C stretching from Me₃ Si substituted olefinic linkagesα to fluorine-substituted olefinic linkages and fluorine-bearing C═Cbonds, respectively. Microanalysis: Found C 50.18; H 5.98; Si 15.20; F20.20 (cf. PTMSA: C 61.21; H 10.28; Si 28.63).

EXAMPLE 12 Metallation of Bromine-Replaced PTMSA

A solution of 0.4 g bromoacetylene-trimethylsilylacetylene copolymer(prepared by bromination of PTMSA according to Example 10) in 25 ml THFwas cooled to -45° C. and 2.91 ml of 1.4 M sec-BuLi in cyclohexane (40.7mmol) added dropwise with stirring. After a further 30 min. of stirring,dry, benzoic acid-free benzaldehyde (0.414 ml, 40.7 mmol) was added in asingle portion and the mixture allowed to warm to ambient temperature.The crude product (0.2 g) was obtained by precipitation with 5 volumesmethanol. After drying, it exhibited the expected IR and NMR spectra.This example illustrates the technique of sequential modifications ofthe basic PTMSA structure. It also provides a means for generatingstable, trappable vinylic lithium bonds on the PTMSA conjugatedbackbone, thereby opening up an additional wide range of structuralmodifications.

EXAMPLE 13 Addition of ICl to PTMSA

A solution of 200 mg (2.04 meq) of PTMSA in 4 ml CCl₄ was treated with363 mg (2.24 mmol) ICl. A vigorous reaction occurred. After 20 hrsstirring at room temperature, a large amount of black precipitate hadformed. The remainder of the product was precipitated by addition of 10volumes methanol, isolated by filtration, washed thoroughly with moremethanol, then dried. Microanalysis gave: Found, C 47.52; H 3.52; Si2.96; I 29.04; Cl 15.47. The microanalysis results suggest that, in thiscase, both silyl replacement by I and addition of ICl across thebackbone have occurred. This backbone addition is undesirable since itlowers the conductivity of the resulting materials. However, asubsequent treatment with a tertiary amine (triethylamine,diazabicycloundecene, etc.) can be used to eliminate the elements of HX(X=F, Cl, Br, I) and, thereby, reestablish the PTMSA backbone ofalternating single and double bonds.

EXAMPLE 14 Doping and Conductivity of PTMSA and Derived Copolymers

PTMSA and materials derived from it by the synthetic manipulationsdescribed in the previous examples can be doped by either vapor-phase orsolution methods which are known to those skilled in the art. Suitabledopants will include electron acceptors (I₂, AsF₅, FeCl₃, and the like)or donors (alkali metals, Li benzophenone, Na naphthalenide, etc.). Thefollowing procedure is illustrative of vapor phase doping techniques:PTMSA (7 mg) was compacted by means of a handpress into pellets 3 mm indiameter by 1 mm in thickness. Doping was accomplished by exposure ofthese pellets to I₂ vapor in an otherwise inert atmosphere for varyingperiods of time depending on the level of doping desired. This bringsabout a rapid change in color from the lemon yellow of undoped PTMSA toa metallic black characteristic of the doped material. Doping levelswere determined gravimetrically on an electronic microbalance.Conductivities were measured by a standard four-probe apparatus.

EXAMPLE 15 Polymerization of Phenylacetylene with WCl₆.4n-BuLi

A dry, degassed toluene solution of 0.0925 g WCl₆ was treated with 4 eq.of 2.1 n-BuLi solution in hexane. The resulting catalyst solution wasstirred for 30 min. at ambient temperature whereupon 0.79 ml of purifiedphenylacetylene was added by syringe. The resulting mixture was stirredat room temperature for 18 hours. The reaction was then quenched byaddition of 8 volumes methanol. The precipitated product was isolated byfiltration, washed well with methanol and dried in vacuo to afford 0.5 g(70% yield) of deep red poly(phenylacetylene). Gel permeationchromatography showed this material to have a "polystyrene equivalent"molecular weight of 250,000 in a monomodal molecular weightdistribution. Infrared and NMR spectroscopy and elemental analysisresults were all consistent with the assigned structure.

EXAMPLE 16

Several other representative substituted acetylenes were polymerized bya procedure identical to that in Example 1. The yields and molecularweights (for the soluble polymers) are shown in Table 2 below. It isnoteworthy that acetylenes with coordinating substituents arepolymerized by this catalyst.

                  TABLE 2                                                         ______________________________________                                        Polymerization of Substituted Acetylenes                                      by WCl.sub.6.4 -n-BuLi                                                        Acetylene         Yield   Modal MW                                            ______________________________________                                        1, 5-hexadiyne    50      insoluble                                           2-ethynylpyridine 17      20000                                               propargyl chloride                                                                              30       4000                                               1-phenyl propiolic acid                                                                         25      10000                                               ______________________________________                                    

From the foregoing description, one skilled in the art can easilyascertain the essential characteristics of this invention, and withoutdeparting from the spirit and scope thereof, can make various changesand modifications of the invention to adapt it to various usages andconditions.

What is claimed is:
 1. A process for preparing a polymer containingrepeating units of --(XC═CR₄)-- and --(C(Si(CH₃)₃ ═CH--comprisingreacting a first soluble polymer with a reagent effective to causeelectrophillic or nucleophilic substitution of R₁ R₂ R₃ Si-- groupsthereof by X, said first polymer having a molecular weight (M_(n))≧about10,000 and being a polymer of one or more monomers of the formulaR--C═C--R₄ wherein R is R₁ R₂ R₃ in which each of R¹ R₂ R₃ Si is C₁₋₄(n- or sec-)-alkyl; C₂₋₄ -alkenyl; C₆₋₁₄ -aryl; C₇₋₁₇ -heteroaryl; C₇₋₁₇-alkaryl; C₇₋₁₇ -aralkyl; C₃₋₁₃ -cycloalkyl; C₂₋₄ -(n- or sec-)-alkyl inwhich one CH₂ group is replaced by --O--, --S--, --COO--, or --OOC--;C₆₋₁₄ aryl or heteroaryl in which one aryl CH is substituted by --O--,--S--, --COO--, or --OOC--; H, or groups recited for R₁, R₂, and R₃ ; R₄is H or one of the groups recited for R₁, R₂, and R₃, except C₂₋₄-alkenyl, with the provisos that R and R₄ must not both be H at the sametime and that the combination of R and R₄ be sterically compatible.
 2. Aprocess of claim 1 wherein R₄ is H.
 3. A process of claim 2 wherein R₁,R₂ and R₃ are methyl.
 4. A process of claim 3 wherein X is halo or acyl,H, or D.
 5. A polymer produced by the process of claim 4 having amolecular weight (Mn)≧about 30,000.
 6. A process of preparing a polymercontaining repeating units of --(YC═CR₄)--, and --(C(Si(CH₃)₃--CH)--comprising performing the process of claim 1 and then reactingthe resultant (XC═C--R₄)-containing polymer with a reagent effective tocause substitution of X-- groups thereof by Y--.